Design and fabrication of a piezoelectric MEMS xylophone transducer with a flexible electrical connection

Abstract

We develop a method for the design and fabrication of a miniaturized multichannel piezoelectric xylophone acoustic transducer with an integrated flexible ribbon cable for electrical connectivity. This transducer works in air or underwater and it is designed to be implantable for in vivo animal testing. The transducer and ribbon cable are fabricated separately using microelectromechanical systems (MEMS) techniques, and bonded with a customized wire-epoxy bonding technique. The transducer has a xylophone structure which consists of four piezoelectric bimorph cantilevers of varied lengths each tuned to a target frequency bandwidth. A parylene ribbon cable extends from the base of the xylophone to an electrode bay for external monitoring. Cantilever tip deflections are measured in response to voltage excitation to confirm the transducer functionality in air and underwater as well as to validate the finite element analysis (FEA) model, which is developed to design the transducer and study the acoustic structure interaction of the cantilever beam in a viscous fluid environment. The frequency response of the model matches closely with the measured results.